A contact in a semiconductor integrated circuit allows electrical connection between metal conductors and circuit elements, e.g., transistors, in the semiconductor integrated circuit substrate. Generally, an oxide layer is deposited or otherwise formed on the substrate. A hole is formed in the oxide layer, and then filled with a conductive material, e.g., a via, to provide the electrical connection between the circuit elements and the metal conductors.
One technique currently used to form contacts involves using physical vapor deposition (PVD) to deposit a refractory metal, such as MoSix or TiN as a barrier to prevent electro-migration, followed by a 200° C. to 450° C. PVD AlSiCu deposition. This technique, however, does not produce consistently filled contacts, or provide required electro-migration resistance at the newer submicron contact size and circuit element current densities.